Radio apparatus



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c. E. BONINE RADIO APPARATUS Filed Aug. 12, 1923 Patented Dec. 25, 1928.

UNITED STATES A 1,696,263 PATENT OFFICE.

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Application flied August 12, 1922. Serial No. 581,308.

My invention relates to apparatus for amplifying and detecting, or vice versa, undulatory or alternating currents employed for any 1 purpose, and particularlyhigh frequency oscillations or alternating current such as commonly employed in systems of radio telegtion that, particularly when the thermionic" amplifiers are substantially similar in size or 3 electrical characteristics, the impedance of the inductive reactance, auto-transformer, or

- windings of the tWo-windinotransformers,

progressively change, and preferably increase in magnitude in the successive stages.

Further in accordance with my invention,

when the alternating currents or oscillations are of radio frequency, the inductive reactthe two-winding transformers are of the so-' ances, auto-transformers, and windings of Y called radio frequency types, that is, proportioned with respect to the radio frequency involved.

Further in accordance with my invention, the aforesaid radio frequency inductances or transformer windings are utilized in such re- 'lation that the anode circuits of the amplifiers are substantially aperiodic or non-oscillatory and it is a. further characteristic that no sharp resonance prevails in the plate circuits, but on the contrary, the proportions are such that with given windings the apparatus is operable over a relatively wide range of wave lengths.

Further in accordance with my invention, the radio frequency transformer or inductive reactance comprises a winding or windings in single layer of extremely small conductor having theconvolutions spaced from each other for minimizing distributed capacity, and in the case of a twowvinding transformer the primary and secondary are positioned close with respect to each other for effecting close coupling. 7

My invention resides in the features of construction, arrangement and combination hereinafter described and claimed.

For an illustrationof some of the various forms my invention may take, reference is to be had to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of one of various circuit arrangements in which my cou ling means may be employed.

ig. 2 is a fragmentary diagrammatic illustration of the employment of inductive reactance or auto-transformer coupling.

Referring to Fig. 1, L is a loop or coil aerial for absorbing, as from a natural medium, energy of high frequency waves represent-ing, for example, a signal or message transmitted between stations without the empioyment of intervening conductors. It will un rstood, however, that any other suitable orm of absorption structure, as the usual antenna and its couplings, ma be employed. Shunting the inductance is the usual variable tuning condenser C, one ter minal' of which is connected to the grid 9 of the first stage thermionic amplifier V having the anode a and cathode or filament f, the amplifier V being the first of a series of amplifiers V-V inclusive, all similarly provided with grid, anode and cathode. The fila ments or cathodes of the amplifiers are heated by current from the battery A, each filament being provided with the usual adjustable resistance r. Bridging the terminals of the battery A is the resistance R, with which coacts the movable contact I) connected to the other terminal of the aforesaid condenser'C.

With the anodes of the successive amplifiers are connected similar terminals of the transformer primaries P whose other terminals connect to the positive terminal of the uni-directional source of current for the anode circuits, the same being indicated as a battery B, whose negative terminal is connected to the various cathodes or filaments. The secondaries S of the transformers are connected, on the one hand, to the grids of the next stages in the series, and their other terminals are connected to the aforesaid slider contact I) of the stabilizer resistance; in the case of the secondary S of the transformer of the anode circuit of the amplifier V one terminal is connected to the cathode or filament of the detector tube D and its other terminal is connected to the grid of said detector through the condenser C shunted by the usual resistance r For the anode circuit of the detector D there may be provided a separate battery or source of current B, whose positive terminal connects with the anode of the detector D and whose negative terminal connects to the slider contact 6 movable along the potentiometer resistance R connected across the aforesaid battery A. g

In the anode circuit of the detector D is connected the primary P of an audio frequency transformer whose secondary S 15 connected to the grid of the amplifying tube V. Similarly, in the anode circuit of the amplifier V is connected the primary wmding P of an audio frequency transformer, and the aforesaid battery B; the secondary S of the transformer has its one terminal connected to the grid of the second amplifier tube V, in whose anode circuit is connected the signal translating instrument, as a telephone The transformers associated with the amplifiers VV are radio frequency transformers whose primaries and secondaries are preferably close to each other to effect close coupling and the inductance and impedance of whose primaries P progressively increase with the succession of stages of amplification that is to say, the inductance and impedance of the primary P in the anode circuit of the amplifier V is greater than the inductance and impedance of the primary P in the anode circuit of the amplifier V, and there is preferably a similar increase in inductance and impedance of each succeeding stage. The same is true of the secondaries S, the ratio of transformation being anything suitable or desirable, but preferably unity for relatively short wave lengths, as for example, 200 to 500 meters; but in the case of longer wave lengths the ratio of transformation is preferably greater than unity.

By preference, the impedance of each primary P is substantially equal to the impedance within the associated amplifier, as for example, the impedance between the anode and cathode of the associated amplifier in whose anode circuit such primary is connected.

By preference, the number of turns of the second and each of the successive primaries P bears a substantially constant ratio to the number of turns of the primary P of the immediately preceding transformer of the series, when each of said primaries consists of a single layer winding. Without limitation of my invention thereto, it may be stated that this ratio of increase of number of turns may be substantially constant and may be of the order of 1.25, from which it follows that the number of turns of the successive transformer primaries and secondaries is in ge0 metric progression, the inductances of the windings also increasing at increasing rate, but not strictly in accordance with the geometric progression. In general, however, the inductance of the primaries and secondaries progressively increase with the succession of sta es, this relation having been found by me to e essential for best effects in multi-stage radio frequency amplification. And this progressive increase of inductance and impedance of the transformer windings is of particular advantage where the several primaries P are connected to one and the same stabilizer R, b, or equivalent, serves to stabilize the several stages with which the transformer windings are associated.

While by preference there are employed for coupling the anodes of the successive amplifiers to the grids of the next following amplifiers two-winding transformers as described in connection with Fig. 1, it will be understood that for such transformers may be substituted inductive rcactance or auto transformer couplings as indicated at I, Fig. 2. In this case agaln the successive inductances or auto-transformers I similarly increase in inductance and impedance, and when constituted of a single layer winding, the number of turns of the windings preferably increase in geometric progression, as described in connection with Fig. 1.

By way of example merely, it may be stated that when the amplifiers V-V are the socalled radiotrons UV now commonly utilized, and for a wave length range of 200 to 500 meters, the primary P and secondary S of the first stage coupling each comprises a single layer of ninety turns of insulated copper conductor having a diameter of .0015 inch, the windings having a diameter of the order of thirteen-sixteenths of an inch and 1 each winding being so spaced that its length is about three-eighths of an inch. The windings P and S of the succeedinv transformers are similarly wound in single layers, with conductor of the aforesaid $126, but with increased number of turns and length of winding, the coils PS of the second transformer each having 112 turns; the primary and secondary of the next transformer having 140 turns; and the primary and secondary of the fourth transformer having 175 turns each.

It is therefore apparent that the transformers for the successive stages are not identical in construction, but increase in inductance and number of turns, and it will be understood that if the number of stages be further increased, such numbers of turns, diameter and length of windings may be employed as to effect the suitable progressive increase in impedance and inductance.

In the practice of my invention, particularly in connection with that feature thereof relating to the increase. of inductance of the coupling means in successive stages, it is prcferred that the capacity of the tuning con- 126 denser C shall be small, and in general the smaller the better within operative limits, as compared with the magnitude of the inductance of the associated windin or coil, as the loop L or equivalent, whereby the induc- 130 the and fore given of the nunibers of turns of the primaries P and secondaries S for different stages, assumin a wave length range of 200 to 500 meters, the maximum capacity of the condenser C for a'wave length of 500 meters is preferably of the order of .00025 microfarad. With the capacity of such magnitude for receiving 500 meter waves, the associated inductance either in the coil L or other. 1n-- ductance preponderates or predominates over the capaclty as a tuning element.

What I claim is: 1. In a multi-stage amplifying system, the

. combination with successive thermionic amof inductive means for coupling said the inductance of the coupling later stage being greater than the inductance of the coupling means of an earlier stage.

2. In a multi-stage amplifying system, the combination with successive thermionic amplifiers, of inductive means for coupling said amplifiers, the magnitudes of the inductances of said coupling means increasing in a substantially geometric progression throughout the several stages.

3. In a-multi-stage amplifying system, the combination with successive thermionic amplifiers, of inductive means for coupling said amplifiers, said coupling means comprising windings whose number of turns'in a later stage is greater than the number of turns in an earlier stage.

4.- In a multi-stage amplifying system, the

combination with successive thermionic amp phfiers, of transformers for coupling said amplifiers, each of said transformers comprising primary andsecondary windings, the number of turns of the primaries of said transformers being greater in a later stage than in an earlier stage.

5. In a multi-stage amplifying system, the combination with successive thermionic amplifiers, of transformers for coupling said I amplifiers, each ofsaid transformers comprising primary and secondary windings, the magnitudes of the inductance of the pri- J maries of said transformers being greater in a later stage than in an earlier stage, the number of primary and secondary turns in each transformer being substantially equal. 6. In a multi-stage amplifying system, the

combination with successive thermionic am-' phfiers, of transformers for coupling said" amplifiers, each ofisaid transformers comprising priinary and secondary windings, the magnitudes of the inductance and the number of turns of the primaries of said transformers'being greater in a later stage than in member stage, the number of primary and secondary turns in eachtransformerbeing substantially equal.

. In a multi-stage amplifying system, the

combination with successive thermionic am plifiers, of transformers for coupling said amplifiers, each of said transformers comprising primary and secondary-windings, the

magnitudes of the inductance and the numprising primary and secondary windings, the j magnitudes of the inductance of the primaries of said transformers being greater in a later stage than in an-earlier stage, the primary and secondary windings of said transformers consisting of single layer windmgs.

9. In a multi-stage amplifying system, the combination with successive thermionic amplifiers, of transformers for coupling said amplifiers, each of said transformers com prising primary and secondary windings, the number of turns of the primaries of said transformers being greater in a later stage than in an earlier stage, the primary and secondary windingsof said transformers consisting of single layer windings.

10. A system for amplifying radio frequency currents in successive stages, comprising the combination with thermionic radio frequency amplifiers in the several stages, of inductive means for coupling said amplifiers, the inductance of the inductive couling means of a later stage being of the order of 1.25 times that of the inductive coupling means of a preceding stage.

11. A system for amplifying radio frequency currents in successive stages, c0mprising thecombination with thermionic ra dio frequency amplifiers in the several stages, of inductive means for coupling said amplifiers, the magnitude ofthe inductance of said coupling means in a later stage being greater than the inductance of the coupling means of an earlier, and means common to the several stages for stabilizingthem.

12. .A system for amplifying radio he quency currents in successive stages, comprising the combination with substantially similar thermionicthree-electrode radio fre- Y quency amplifiers in the several stages, of inductive means for coupling the output to the prising the combination with substantially similar thermionic three-electrode radio frequency amplifiers in the several stages, of radio frequency transformers having r1- mary and secondary windings for coup ing the output to the input circuits of sad amplifiers, the magnitude of the mductance of the transformer primary of a later stage bemg reater than the-inductance of the transormerprimary of an earlier stage.

14. A system for amplifying radio frequency currents in successive stages, comprising the combination with substantially similar thermionic three-electrode radio frequency amplifiers in the several stages, of radio frequency transformers having primary and secondary windings for coupling the output to the input circuits of said amplifiers, the magnitude of the inductance of the transformer primary of a later stage being greater than the inductance of the transformer primary of an earlier stage, and the inductance of a transformer secondary of a later stage being greater than the inductance of the transformer secondary of an earlier stage.

15. A system for amplifying radio frequency currents in successive stages, comprising the combination with substantially similar thermionic three-electrode radio frequency amplifiers in the several stages, of

being greater than the inductance of the transformer cprimary of an earlier sta e, the primary an secondary windings 0 each stage having substantially equal number of turns.

16. A system for amplifying radio frequency currents in successive stages, comprising the combination with substantially similar thermionic three-electrode radio frequency amplifiers in the several stages, of radio frequency transformers having primary and secondary windings for couplin the output to the input circuits of said amplifiers, the magnitude of the inductance of the transformer primary of a later stage being greater than the inductance of the transformer primary of an earlier stage, and means common to the several stages for stabilizing them.

17. A system for amplifying radio frequency currents in successive stages, comprising the combination with substantially similar thermionic three-electrode radio frequency amplifiers in the several stages, of inductive means coupling the output to the input circuits of said amplifiers, the coupled output and in put circuits being aperiodic, the inductance of the coupling means of a later stage being greater than the inductance of the coupling means of an earlier stage.

In testimony whereof I have hereunto affixed my signature this tenth day of August, 1922.

CHARLES E. BONIN E.

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Patent No. 1,696, 263.

Granted December 25, 1928, to

CHARLES E. BONINE.

, It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 116, claim 11, after the word "earlier" and before the census insert the word "stage"; page 4, line 63, claim 17, for the words "in put" read "input"; and that the said Letters Patent should be resd with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of March, A. D. 1929.

(Seal) M. J. Moore, Acting Conmissioner of Patents. 

